I really hate people sometimes

Yeah.....a student in my wildlife class stole my field lab book.  There are only 3 students it could be...none are fessing up.  Damn book is worth 7% of my grade!  That could be a difference in letter! I emailed my professor when I noticed it gone as well as the three students asking for it back. So far one has denied having it and the other two haven't responded and I haven't heard anything from the prof yet...so I'm thinking that I'm probably screwed on this one. FML